New 50 to 125 DC 4 pin CDI problems
 

Have a 07 08 HI bird 110 atv. Went to start yesterday no spark. Had a new 4 pin cdi from 2016 and starter would barely turn it over and would backfire and not run good. Like ignition was way to advanced l. I put old cdi in front of heat duct all night. Tried starting it again today and same thing backfiring and not running well. Put old cdi back on and started up and is running fine again. Anyway if I ever have to replace it what's the best way to retard ignition timing.